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Biomedical subjects

H Pakkenberg

Publications and source records attributed to H Pakkenberg.

85 records · Page 5Linked to original sources

No global neocortical nerve cell loss in brains from patients with senile dementia of Alzheimer's type.

Precise estimates of total neuron numbers in neocortices of 11 women, mean age 82.6 years (range 79-88) with severe senile dementia of the Alzheimer's type (SDAT) were compared with similar estimates in 10 cognitively normal women of comparable mean age (84.1 years; range 74-92). The total mean nerve cell number in the SDAT group was 16.9 x 10(9) with a coefficient of variation (CV = SD/mean) = 0.14, whereas mean total neuron number in the control group was 18.1 x 10(9), CV = 0.18. In a material of this size the reduction of 6% in neocortical cell number in the SDATs is neither statistically nor biologically significant. Nevertheless, all patients with SDAT were severely demented, having a mean score of 5.6 on a 1-7-scale of dementia. This contrasts with the nondemented individuals who had lived an independent life at home until shortly before death. The SDAT patients showed a rather consistent reduction in cortical volume by 14%, an atrophy that was solely due to a reduced cortical thickness. In addition, all had multiple neocortical plaques (Bielschowsky silver stain).

Aged↗

MPTP-induced Parkinsonism in minipigs: A behavioral, biochemical, and histological study.

Fourteen male Göttingen minipigs were used in this study. Nine were administered N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at a dosage of 1 mg/kg/day, SC, for 6 days, the last five pigs received saline injections for 6 days. All MPTP-treated animals developed Parkinson symptoms, i.e., muscle rigidity, hypokinesia, and impaired coordination within 5 days. The brain levels of dopamine (DA), and its major metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were determined in caudatum and putamen 2, 14, and 93 days (n = 3/time point) after the last drug administration. In eight of the MPTP-treated animals, striatal DA, DOPAC, and HVA concentrations were reduced from 50 to 95% compared to control animals at all time intervals. Animals with the lowest striatal DA concentrations showed the most severe signs of Parkinsonism. The number of cells in substantia nigra (SN) showed a decline only 3 months after MPTP treatment. The minipigs represent a nonprimate model of MPTP-induced parkinsonism syndromes lasting at least months.

3,4-Dihydroxyphenylacetic Acid↗